Method for trimming blanks



av. 12', 1931. R. L. wuLcox IETHOD FOR TRIMMING, BLANKS Original Filed Feb. 13, 19 287 F m g 3 gmmtoz Havana 5375? m1- cox Patented Nov. 17, 1931 NITED STATES PATENT OFFICE RICHARD LESTER WILCOX, OF WATERIBURY, CONNECTICUT, ASSIGNOR TO THE WATER- BURY FARREL FOUNDRY AN D MACHINE COMPANY, OF WATERBURY, CONNECTICUT,

A CORPORATION OF CONNECTICUT METHOD non rnmmme BLANKS Original application filed. February 13, 1928, Serial No. 254,093. Divided and this application filed February 8, 1930.

This invention relates to means and method for trimming blanks, whereby the heads thereof may be given a polygonal cross section, such as square, hexagonal or octagonal shape, or ,a cross section having fiat sides or the like, the term polygonal as used herein including all such shapes It is the object of this invention, among other things, to give such trimmed cross section to a blank by an entire cutting of the metal without tearing it, thus producing a clean and unbroken cut surface on the blank.

These, and other desirable objects of the invention, are obtained by first passing a cutting die over the head of the blank so as to trim the same for a portion of its length, and thereafter holding the cutting die while the head is projected therethrough.

The details and arrangement of parts used in my new and improved means and method for trimming blanks will be apparent from an inspection of the accompanying drawings in connection with the description herein, and wherein a preferred embodiment of the means and method is disclosed for the purpose of imparting an understanding of the same.

This application is a division of the subject matter of anapplication filed February 13, 1928, Ser. N 0. 254,093, now Patent No. 1,748,321 issued February 25, 1930.

In the drawings, wherein like characters of reference indicate corresponding parts in the several figures;

Figure 1 is a sectional elevation of the punch and die of a trimming machine and adjacent parts in the relative positions occupied by them as the blank to be trimmed is placed therebetween;

Figure 2 is a similar view showing the shank of the blank projected into the punch and the underside of the head against the outer end thereof with the cutting die in position to begin the cutting operation;

Figure 3 is a similar view with the die and punch when adjacentto each other; and

Figure e is a view with the parts in substantially the same position as in Figure 3, except that the trimmed blank has been projected through the die by the knockout mechanism.

Serial No. 426,821.

Referring to the drawings, 10 indicates the punch having an opening 11 therein of substantially the same size as the shank 12 of the blank, which is held by any convenient means in a punch holder 13; 14 is the gate of the trimming machine, which reciprocates in the usual manner toward and away from the punch holder 13. v

lVithin the gate is a backing block 15, having an opening 16 therein, and connected therewith is the die, plate 17 upon which is a die holder 18. Secured in the die, plate by any convenient means is the trimming die 19. The opening 20 in this die is substantially the same shape in cross section as that of the finished head of the blank.

In operation the blanks are successively presented with their axes coincident with the openings 11 and :20, substantially as shown in Figure 1, with the head adjacent to the trimming die. Thereafter, during the movementof the parts, the open space between the punch and die is reduced until they are in the position substantially as shown in F igure 2. During this time the pressure upon the face of the head 21 of the blank is such that the shank 12 is forced into the opening 11 in the punch and the end face of the head abuts against the outer face of the punch 10.

The continued movement of the parts causes the died 19 to pass over 'the die 21 of the blank until the opposite faces of the punch and die are in substantially the relative position shown in Figure 3, when the punch and die are in rest positions. Durin this latter movement the head of the blank is trimmed for a portion of its length as the trimming die passes thereover.

The chip, fin or shaving 22 formed around the head by the trimming die occupies the space-between the faces of the die and punch. While the punch and die are at rest and in these relative positions, the knockout rod 23 moves forwardly, engages the end of the shank 1:2, if not already in contact therewith, and projects the blank through the opening 20 in the die and the finished product 24 drops through the opening 16. The passage of the head of the blank through the die under the impulse of the knockoutmechanism causes the die to complete the trimming operation and the fin 22 drops from between the punch and die as the space therebetween is increased by the movement of the parts for the next succeeding operation.

Thus, relatively to the punch, the blank is trimmed by two separate actions; first, while the blank is at rest in the punch and the space between the punch and die is being reduced; and second, while the punch and die are at rest and the blank is in motion through the die under the pressure of the knockout mechanism.

One portion of the trimming operation is thus performed while the space between the die and punch is being reduced and the remainder of the trimming while the punch and die are in a substantially fixed relative position.

What I claim as new and desire to secure by Letters Patent, is:

1 The method of trimming the heads of screws, bolts and the like, which consists in bringing the head of a previously headed blank into contact with a head trimming die, moving the trimming die with the blank until the underside of the head thereof engages an abutment and is supported b the shank of the bolt within an opening 0 substantially the same size thereof and thereafter continuing the movement of the trimming die over the head of the blank for a portion of the length of the head and thereby trimmin the head for a portion of its length only and finally trimming the' untrimmed portion of the head by moving the blank away from the abutment and through the now stationary trimming die.

2. The method of trimming the heads of screws, bolts and the like, which consists in brin ing the head of a previously headed bla into contact with a head trimmin die, moving the trimming die with the blanl i until the underside of the head thereof engages an abutment and thereafter continuing the movement of the trimming die over the head of the blank until it has trimmed the same for a portion of its length and finally trimming the untrimmed portion of the head by moving the blank away from the abutment and through the now stationary trimming die, the blank from the time it is first engaged by the trimming die until completely trimmed travelling in two diametrically opposite directions.

In testimony whereof, I have hereunto affixed my signature.

RICHARD LESTER WILCOX. 

